I've noticed that when I set up a Highlighting style with a background color, the background color is centered (as I would expect it to be) in the sample shown in the highlighting palette:

But when I apply that highlighting style in a Bible or other book, the text is not vertically centered within the background color.

See how the color drops down below the line rather than having a bit above and a bit below the line?
I think this is not aesthetically pleasing.